greenboard

[green-bawrd, -bohrd] /ˈgrinˌbɔrd, -ˌboʊrd/

noun

1.

a green chalkboard or blackboard.

Origin

Examples from the web for greenboard

If greenboard or other moisture-resistant drywall got wet, replace it.
The drywall was replaced with a greenboard type of drywall.
greenboard is more resistant to moisture than the average dry wall.